Binary files use a particular, well-defined encoding that determines how the binary data in the file should be interpreted. For example, the JPEG image encoding standard describes a mapping between the binary data in an image file and a visual rendering of that image. A file format is used to specify how to convert the data contained in the file, typically binary data in 1s and 0s, to information useful to humans. One method of identifying the type of a file is to store information regarding the format in the file itself. Such information is placed in specific locations within the file, such as in metadata contained in a file header at the beginning of the file or elsewhere in the file. The headers, including file type information, can be human readable or binary.
In some document and file management systems, files or items in the system may be associated with standardized, generic typing information, for example, a “MIME type.” Multipurpose Internet Mail Extensions (MIME) is an Internet Engineering Task Force (IETF) standard that describes a mechanism for specifying binary file encodings in a standardized way. A string that describes a binary file type is usually referred to as a “MIME type”. MIME types were originally used to identifying what type of file was attached to an e-mail, independent of the operating system of the sender and recipient. MIME types are now used more generally to specify file types. File name extensions (e.g., “.txt” for plain text) is another way to specify the format of a file.